According to the reports of police, human heads and decapitated bodies were found in Guatemala's capital, accompanied by threatening notes targeting high ranking government officials.

CNN reported on Friday that the notes were addressed to Interior Minister Carlos Menocal and to Eddy Morales, Guatemala's director of prisons.

The BBC has reported that police in Guatemala City has also said that based on the contents of the notes, they blame drug gangs for the killings.

"This is happening because of the mistreatment and the injustices in the country's jails," said one of the messages read out by Menocal.

The BBC also said that the killings come after a series of arrests of alleged high-profile drug traffickers, and after new restrictions were imposed in the country's prison system. The restrictions included more frequent transfers to different prisons to prevent convicts from continuing to run criminal empires from behind bars.

The slayings came three days after the resignation of Carlos Castresana, director of a U. N. commission to combat alleged links between the Guatemalan government and organized crime. He stepped down saying the Guatemalan government had reneged on a pledge to reform the country's justice system.

Criminal gangs were taking advantage of a vacuum left by the resignation "to wreak havoc," said a police spokesman. (With Inputs from Agencies)